Accident Overview
A Mooney M20J airplane experienced a significant loss of engine power during the initial climb after a normal takeoff. The pilot executed a forced landing onto a golf course adjacent to the airport. The aircraft came to rest upright, but the engine was torn away from the firewall and the airframe sustained substantial damage.
Engine Examination
Post-accident examination of the engine revealed that the Bendix single drive, dual magneto mounting flange was fatigue fractured. The fracture pattern was consistent with inadequate torque being applied to the mounting nuts.
Maintenance History
The airplane had been operated for approximately 275 hours since its most recent annual inspection, which occurred about one year prior to the accident. The logbook entry for that annual inspection specifically included maintenance performed on the magneto.